One of the ways that you can prevent human rights violations is to be sensitive to signals and not be scared of investigating them further.
For example, if your classmate often has bruises, you can take them aside to ask if everything is ok and ensure them that you are safe to talk to.
Or, another example, if you hear that the food you're buying was produced with slave labour, try to find out more and talk to others about it, making them also away of it, so that you can boycott it.
